This reflects the change made in chrome:
https://chromium-review.googlesource.com/c/chromium/src/+/2387554

I somehow thoughts that DefaultJob didn't need the fence, but
TSAN detected the same kind of failures after
9e8c54f8 started using AcquireTaskId.

Drive-by: move delegate outside the loop in Join() to avoid releasing
the task_id many times.

Change-Id: I2ab6bf1bd3eeb7a66e39f20a7e0aa61a9c1ebc44
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2401964Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69818}